1. Download this file to the “src/” directory

gd_image.inc.diff

--- gd_image.inc.orig   2019-12-29 12:08:59.320754190 +0100
+++ gd_image.inc.php    2019-12-29 12:21:49.570063291 +0100
@@ -106,10 +106,12 @@
         $this->use_anti_aliasing = $aFlg;
         if( function_exists('imageantialias') ) {
             imageantialias($this->img,$aFlg);
-        }
+       }
+/* Do not throw exception if function "imageantialias" does not exist
         else {
             JpGraphError::RaiseL(25128);//('The function imageantialias() is not available in your PHP installation. Use the GD version that comes with PHP and not the standalone version.')
        }
+*/
     }
 
     function GetAntiAliasing() {

2. Patch with

$ patch < gd_image.inc.diff
patching file gd_image.inc.php
$